Methods and Apparatus for Cleaning Semiconductor Wafers

ABSTRACT

A method for cleaning semiconductor substrate using ultra/mega sonic device comprising holding a semiconductor substrate by using a chuck, positioning a ultra/mega sonic device adjacent to the semiconductor substrate, injecting chemical liquid on the semiconductor substrate and gap between the semiconductor substrate and the ultra/mega sonic device, changing gap between the semiconductor substrate and the ultra/mega sonic device for each rotation of the chuck during the cleaning process by turn the semiconductor substrate or the ultra/mega sonic device clockwise or count clockwise.

FIELD OF THE INVENTION

The present invention generally relates to methods and apparatuses forcleaning semiconductor wafer. More particularly, relates to changing agap between an ultra/mega sonic device and a wafer for each rotation ofthe wafer during the cleaning process to achieve an uniform ultra/megasonic power density distribution on the wafer, which removes particlesefficiently without damaging the device structure on the wafer.

BACKGROUND

Semiconductor devices are manufactured or fabricated on semiconductorwafers using a number of different processing steps to create transistorand interconnection elements. To electrically connect transistorterminals associated with the semiconductor wafer, conductive (e.g.,metal) trenches, vias, and the like are formed in dielectric materialsas part of the semiconductor device. The trenches and vias coupleelectrical signals and power between transistors, internal circuit ofthe semiconductor devices, and circuits external to the semiconductordevice.

In forming the interconnection elements the semiconductor wafer mayundergo, for example, masking, etching, and deposition processes to formthe desired electronic circuitry of the semiconductor devices. Inparticular, multiple masking and plasma etching step can be performed toform a pattern of recessed areas in a dielectric layer on asemiconductor wafer that serve as trenches and vias for theinterconnections. In order to removal particles and contaminations intrench and via post etching or photo resist ashing, a wet cleaning stepis necessary. Especially, when device manufacture node migrating to 65nm and beyond, the side wall loss in trench and via during is crucialfor maintaining the critical dimension. In order to reduce oreliminating the side wall loss, it is important to use moderate, dilutechemicals, or sometime de-ionized water only. However, the dilutechemical or de-ionized water usually is not efficient to remove particlein the trench and via. Therefore the mechanical force such as ultrasonic or mega sonic is needed in order to remove those particlesefficiently. Ultra sonic and mega sonic wave will apply mechanical forceto wafer structure, the power intensity and power distribution is keyparameters to control the mechanical force within the damage limit andat the same time efficiently to remove the particles.

Mega sonic energy coupled with nozzle to clean semiconductor wafer isdisclosed in U.S. Pat. No. 4,326,553. The fluid is pressurized and megasonic energy is applied to the fluid by a mega sonic transducer. Thenozzle is shaped to provide a ribbon-like jet of cleaning fluidvibrating at mega sonic frequencies for the impingement on the surface.

A source of energy vibrates an elongated probe which transmits theacoustic energy into the fluid is disclosed in U.S. Pat. No. 6,039,059.In one arrangement, fluid is sprayed onto both sides of a wafer while aprobe is positioned close to an upper side. In another arrangement, ashort probe is positioned with its end surface close to the surface, andthe probe is moved over the surface as wafer rotates.

A source of energy vibrates a rod which rotates around it axis parallelto wafer surface is disclosed in U.S. Pat. No. 6,843,257 B2. The rodsurface is etched to curve groves, such as spiral groove.

To uniformly apply right amount of mega sonic power to entire wafer iscritical for the cleaning process. If the mega sonic power is notuniformly applied on the wafer, the portion of wafer receiving less megasonic power will not be cleaned well, and leaving particles andcontamination on the portion of the wafer, and portion of waferreceiving extra mega sonic power may cause the damage of devicestructure on the wafer due high pressure and high temperature micro jetgenerated by implosion of bubbles.

It is needed to have a better method for controlling the mega sonicpower density distribution on the wafer to clean particles andcontamination on surface of wafer or substrate with higher efficiencyand lower structure damages.

SUMMARY

One embodiment of the present invention is to put a mega sonic deviceadjacent to front side of a rotating wafer during the cleaning process,and to change the gap between the mega sonic device and the wafer foreach rotation of the wafer. The gap between mega sonic device and thewafer is changed by turning mega sonic device clockwise and/or countclockwise around an axis parallel to the front side of the wafer.

Another embodiment of the present invention is to put a mega sonicdevice adjacent to front side of a rotating wafer during the cleaningprocess, and to change the gap between the mega sonic device and thewafer for each rotation of the wafer. The gap between mega sonic deviceand the wafer is changed by turning the wafer surface clockwise and/orcount clockwise around an axis parallel to the surface of the mega sonicdevice.

Another embodiment of the present invention is to put a mega sonicdevice adjacent to back side of a rotating wafer, and to change the gapbetween the mega sonic device and the wafer for each rotation of thewafer during the cleaning process. The gap between mega sonic device andthe wafer is changed by turning mega sonic device clockwise and/or countclockwise around an axis parallel to the backside of the wafer.

Another embodiment of the present invention is to put a mega sonicdevice adjacent to back side of a rotating wafer, and to change the gapbetween the mega sonic device and the wafer for each rotation of thewafer during the cleaning process. The gap between mega sonic device andthe wafer is changed by turning the wafer surface clockwise and/or countclockwise around an axis parallel to the surface of the mega sonicdevice.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1D depict an exemplary wafer cleaning apparatus;

FIG. 2 depicts an exemplary wafer cleaning process ;

FIGS. 3A-3B depicts another exemplary wafer cleaning apparatus;

FIG. 4A-4E depict another exemplary wafer cleaning apparatus;

FIG. 5A-5C depict further another exemplary wafer cleaning apparatus;

FIG. 6 depicts a cleaning method;

FIG. 7 depicts another exemplary wafer cleaning apparatus;

FIG. 8 depicts another exemplary wafer cleaning apparatus;

FIG. 9 depicts another exemplary wafer cleaning apparatus;

FIG. 10 depicts another exemplary wafer cleaning apparatus;

FIG. 11 depicts another exemplary wafer cleaning apparatus;

FIG. 12 depicts another exemplary wafer cleaning apparatus;

FIG. 13 depicts another exemplary wafer cleaning apparatus;

FIG. 14 depicts another exemplary wafer cleaning apparatus;

FIG. 15A-15G depicts variety of shape of ultra/mega sonic transducers.

DETAILED DESCRIPTION

FIGS. 1A to 1B show the conventional wafer cleaning apparatus using amega sonic device. The wafer cleaning apparatus consists of wafer 1010,wafer chuck 1014 being rotated by rotation driving mechanism 1016,nozzle 1012 delivering cleaning chemicals or de-ionized water 1032, andmega sonic device 1003. The mega sonic device 1003 further consists ofpiezoelectric transducer 1004 acoustically coupled to resonator 1008.Transducer 1004 is electrically excited such that it vibrates and theresonator 1008 transmits high frequency sound energy into liquid. Theagitation of the cleaning liquid produced by the mega sonic energyloosens particles on wafer 1010. Contaminants are thus vibrated awayfrom the surfaces of the wafer 1010, and removed from the surfacesthrough the flowing liquid 1032 supplied by nozzle 1012.

As shown in FIG. 1C, in order to achieve the least reflection energy,the phase reflection wave r1 (from top of water film) must be oppositeto reflection R2 (bottom of water film), therefore water film thicknessmust equal to:

d=n λ/2, n=1, 2, 3,   (1)

Where, d is the thickness of water film or gap between mega-sonic device1003 and wafer 1010, n is an integer number, and λ is wavelength of megasonic wave in water. For example, for mega sonic frequency of 937.5 KHz, λ=1.6 mm, the d=0.8 mm, 1.6 mm, 2.4 mm, and so on.

FIG. 1D shows the relationship between gap d and mega sonic powerdensity measured by sensor 1002 as shown in FIG. 1A. Power density isvaries from valley value 20 w/cm2 to peak value 80 w/cm2 as gap sizeincrease 0.4 mm, and reach a full cycle in the gap increment of 0.8 mm(0.5λ). It is critical to maintain a gap precisely in order to keep auniform mega sonic power distribution on the entire wafer.

However it is very difficult to keep a uniform gap in such precision inthe reality, especially when the wafer is rotation mode. As shown inFIG. 2, if wafer chuck 1014 is set not 100% vertical to surface of megasonic device 2003, the gap between mega sonic device and surface ofwafer 2010 is reducing from edge of the wafer to center of the wafer. Itwill cause non uniform mega sonic power density distribution from edgeof the wafer to center of the wafer according to data shown in FIG. 1D.

Another possible gap variation is caused by rotation axis of chuck beingnot veridical to surface of wafer 3010 as shown in FIG. 3A and 3B. Thewafer is wobbling when rotating, and FIG. 3B shows gap status afterrotating 180 degree from status as shown in FIG. 3A. The gap at edge ofwafer reduces from a biggest value as shown in FIG. 3A to smallest valueas shown in FIG. 3B. It will cause non uniform mega sonic power densitydistribution on wafer as wafer passing mega sonic device. All such nonuniform power distribution will either cause damage to device structureon the wafer and no uniformly cleaning wafer.

In order to overcome non uniform power distribution caused by variationof gap during chuck rotation, the present invention discloses a methodas shown in FIGS. 4A to 4E. The gap between mega sonic device 4003 andwafer 4010 is changed by motor 4006 as chuck 4014 rotating duringcleaning process. Control unit 4088 is used to control the speed ofmotor 4006 based on speed of motor 4016. For each rotation of wafer 4010or chuck 4014, control unit 4088 instructs motor 4006 to turn mega sonicdevice 4003 clockwise and/or count clockwise around axis 4007. Theincrement of rotation angle of motor 4006 for each rotation of wafer4010 or chuck 4014 is,

Δα=0.5λ/(FN)   (2)

Where, F is width of mega sonic device 4003, λ is wavelength ofultra/mega sonic wave, and N is an integer number between 2 to 1000.

After chuck 4014 rotating N rotations, mega sonic device 4003 turns upto total angle of 0.5 nλ/F, where n is an integer number starting from1.

As shown further in detail in FIG. 6, when the gap changes for eachrotation of wafer or chuck, the mega sonic power density at the sameportion of wafer changes from P1 to P2. When the gap increases totalhalf wavelength of mega sonic wave, the power density varies a fullcycle from P1 to P11. The cycle starting point depends on the gapbetween mega sonic device and portion of wafer, however each portion onwafer will receive full cycle of power density when gap increases halfwavelength of mega sonic wave. In other words, even gap between megasonic device and wafer is not set uniformly due to reason described inFIG. 2, FIGS. 3A and 3B, each portion of the wafer will receive fullcycle of mega sonic power when mega sonic device moves up halfwavelength of mega sonic wave (about 0.8 mm for frequency of 937.5 kHz).This will guarantee each location of wafer to receive the same mount ofmega sonic power density including the same average power density, thesame maximum power density, and the same minimum power density. Theoperation sequence can be set as follows:

Process Sequence 1 (mega sonic frequency: f=937.5 kHz, and wavelength indieonized water=λ=1.6 mm):

Step 1: rotating wafer at speed of w, and w is in the range of 10 rpm to1500 rpm.

Step 2: move mega sonic device to adjacent to wafer with gap d, and d isin the range of 0.5 to 5 mm.

Step 3: turn on nozzle with deionized (DI) water or chemicals, and turnthe mega sonic device on. The power density of mega sonic device is inthe rang of 0.1 to 1.2 watt/cm², and preferred in the range of 0.3 to0.5 watt/cm².

Step 4: for each rotation of chuck 4014, turn mega sonic device 4003clockwise an angle of 0.5λ/(FN), where N is an integer number and in therange of 2 to 1000.

Step 5: continue step 4 until mega sonic device 4003 turns clockwise upto total angle of 0.5 nλ/F, where n is an integer number starting from1.

Step 6: for each rotation of chuck 4014, turn mega sonic device 4003count clockwise an angle of 0.5λ/(FN), where N is an integer number andin the range of 2 to 1000.

Step 7: continue step 6 until mega sonic device 4003 turns countclockwise up to total angle of 0.5 nλ/F, where, n is an integer numberstarting form 1.

Step 8: repeat step 4 to step 7 until wafer is cleaned.

Step 9: turn off mega sonic devices, stop the DI water or chemicals, andthen dry the wafer.

Process Sequence 2 (mega sonic frequency: f=937.5 kHz, and wavelength indieonized water=λ=1.6 mm):

Step 1: rotating wafer at speed of ω, and ω is in the range of 10 rpm to1500 rpm.

Step 2: move mega sonic device to adjacent to wafer with gap d, and d isin the range of 0.5 to 5 mm.

Step 3: turn on nozzle with deionized (DI) water or chemicals, and turnthe mega sonic device on. The power density of mega sonic device is inthe rang of 0.1 to 1.2 watt/cm², and preferred in the range of 0.3 to0.5 watt/cm².

Step 4: for each rotation of chuck, turn mega sonic device clockwise anangle of 0.5λ/(FN), where N is an integer number and in the range of 2to 1000.

Step 5: continue step 4 until mega sonic device turns clockwise up tototal 0.5nλ/F, where n is an integer number starting form 1.

Step 6: turn off mega sonic devices, stop the DI water or chemicals, andthen dry the wafer.

The frequency of transducer can be set at ultra sonic range and megasonic range, depending on the particle to be cleaned. The larger theparticle size is, the lower frequency should be used. Ultra sonic rangeis between 20 kHz to 200 kHz, and mega sonic range is between 200 kHz to10 MHz. Also frequency of mechanical wave can be alternated either oneat a time in succession or concurrently in order to clean different sizeof particles on the same substrate or wafer. If a dual frequency ofwaves are used, the higher frequency f₁ should be multiple integernumber of lower frequency f₂, and the transducer rotating angle rangeshould be the 0.5λ₂n/F, increment or reduction of angle of transducerfor each rotation of chuck should be 0.5λ₁/(FN), which λ₂ is wavelengthof the wave with the lower frequency f₂, λ₁ is wavelength of the wavewith the higher frequency f₁, and N is an integer number between 2 to1000, and n is an integer number starting from 1.

One example of chemicals being used to remove the particle andcontamination are shown as follows:

Organic Material Removal: H₂SO₄:H₂O₂=4:1

Organic Material Removal: Ozone:H₂O=50:1000,000

Particle Reduction: NH₄OH:H₂O₂:H₂O=1:1:5

Metal Contamination Removal: HCl:H₂O₂:H₂O=1:1:6

Oxide Removal: Oxide Removal=HF:H₂O=1:100

FIG. 5A to 5C show another embodiment of wafer cleaning apparatus usinga mega sonic device according to the present invention. The embodimentis similar to that shown in FIG. 4, except that additional rotatingmechanism 5009 is added. Control unit 5088 changes the gap d betweenmega sonic device 5003 and wafer 5010 by instructing motor 5006 andmotor 5009 for each rotation of wafer 5010 or chuck 5014. For eachrotation of wafer 5010 or chuck 5014, control unit 5088 instructs motor5006 to turn mega sonic device 5003 clockwise and/or count clockwisearound axis 4007, and at the same time instructs motor 5009 to turn megasonic device 5003 clockwise and/or count clockwise around axis 5011. Therotation angle increment of motor 5006 for each rotation of wafer 5010or chuck 5014 is,

Δα=0.5λ/(FN)   (3)

Where, F is width of mega sonic device 5003, λ is wavelength ofultra/mega sonic wave, and N is an integer number between 2 to 1000.

After chuck 5014 rotating N rotations, mega sonic device 5003 turns upto total angle of 0.5 nλ/F, where n is an integer number starting from1.

The rotation angle increment of motor 5009 for each rotation of wafer5010 or chuck 5014 is,

Δβ=0.5λ/(LN)   (4)

Where, L is length of mega sonic device 5003, λ is wavelength ofultra/mega sonic wave, and N is an integer number between 2 to 1000.

After chuck 5014 rotating N rotations, mega sonic device 5003 turns upto total angle of 0.5 nλ/F, where n is an integer number starting from1.

FIG. 7 shows another embodiment of wafer cleaning apparatus using a megasonic device according to the present invention. The embodiment issimilar to that shown in FIG. 4, except that chuck 7014 is turnclockwise and count clockwise around axis 7007 by motor 7006 for eachrotation of wafer 7010. More specifically speaking, control unit 7088changes the gap d between mega sonic device 7003 and wafer 7010 byinstruct motor 7006 to turn chuck 7014 around axis 7007 clockwise andcount clockwise.

FIG. 8 shows another embodiment of wafer cleaning apparatus using a megasonic device according to the present invention. The embodiment issimilar to that shown in FIG. 7, except that another motor 8009 is addedto turn chuck 8014 clockwise and count clockwise around axis 8011 by foreach rotation of wafer 8010. More specifically speaking, control unit8088 changes the gap d between mega sonic device 8003 and wafer 8010 byinstructing motor 8006 and motor 8009 to turn chuck 8014 around axis8007 and axis 8011 clockwise and count clockwise.

FIG. 9 shows another embodiment of wafer cleaning apparatus using a megasonic device according to the present invention. The embodiment issimilar to that shown in FIG. 4, except that mega sonic device 9003 isplaced adjacently to the back side of wafer 9010, and is turn clockwiseand count clockwise around axis 9007 by motor 9006. Motor 9006 isattached to chuck 9014. Control unit 9088 changes the gap d between megasonic device 9003 and back side of wafer 9010 by instructing motor 9006to turn mega sonic device 9003 clockwise and count clockwise around axis9007. Mega sonic wave is transmitted to front side of wafer 9010 andwater film 9032 through water film 9034 and wafer 9010. Nozzle 9015supplies DI water or chemicals to maintain water film 9034 between megasonic device 9003 and back side of wafer 9010. The advantage of thisembodiment is to reduce or eliminate a possible damage caused by megasonic wave to device structure on front side of wafer 9010.

FIG. 10 shows another embodiment of wafer cleaning apparatus using amega sonic device according to the present invention. The embodiment issimilar to that shown in FIG. 9, except that another motor 10009 isadded to turn chuck 10014 clockwise and count clockwise around axis10011 by for each rotation of wafer 10010. More specifically speaking,control unit 10088 changes the gap d between mega sonic device 10003 andwafer 10010 by instructing motor 10006 and motor 10009 to turn chuck10014 around axis 10007 and axis 10011 clockwise and count clockwisesimultaneously.

FIG. 11 shows another embodiment of wafer cleaning apparatus using amega sonic device according to the present invention. The embodiment issimilar to that shown in FIG. 4, except that surface of piezoelectrictransducer 11004 has an angle a to surface of wafer 11010. Resonator11008 is attached with piezoelectric transducer 11004, and mega sonicwave is transmitted to wafer through the resonator 11008 and DI water orchemical film 11032. Process sequence 1 and 2 described previously canbe applied here.

FIG. 12 shows another embodiment of wafer cleaning apparatus using amega sonic device according to the present invention. The embodiment issimilar to that shown in FIG. 11, except that additional rotatingmechanism 12009 is added. Control unit 12088 changes the gap d betweenmega sonic resonator 12008 and wafer 12010 by instructing motor 12006and motor 12009. More specifically speaking, for each rotation of wafer12010 or chuck 12014, control unit 12088 instructs motor 12006 to turnmega sonic resonator 12008 clockwise and/or count clockwise around axis12007, and at the same time instructs motor 12009 to turn mega sonicresonator 12008 clockwise and/or count clockwise around axis 12011.

FIG. 13 shows another embodiment of wafer cleaning apparatus using amega sonic device according to the present invention. The embodiment issimilar to that shown in FIG. 4, except that wafer 13010 is placed facedown, and a nozzle array 13018 is placed underneath of front side ofwafer 13010. Mega sonic wave is transmitted to front side of wafer 13010through water film 13032 and wafer 13010 itself A nozzle array 13018sprays liquid chemicals or DI water on to front side of wafer 13010.

FIG. 14 shows another embodiment of wafer cleaning apparatus using amega sonic device according to the present invention. The embodiment issimilar to that shown in FIG. 4, except that additional motor 14040 andlead screw 14005 are added here. For each rotation of wafer 14010 orchuck 14014, control unit 14088 instructs motor 14006 to turn mega sonicdevice 14003 clockwise and/or count clockwise around axis 14007, and atthe same time instructs motor 14040 to move mega sonic device 14003 upand down. For each rotation of wafer 14010 or chuck 14014, motor 14040move mega sonic device 14003 up or down:

Δz=0.5λ/N   (5)

Where, λ is wavelength of ultra/mega sonic wave, and N is an integernumber between 2 to 1000.

After wafer 14010 or chuck 14014 rotating N rotations, mega sonic device14003 moves up to 0.5 nλ, where n is integer number starting from 1.

FIG. 15 shows another embodiment of wafer cleaning apparatus using amega sonic device according to the present invention. The gap betweenmega sonic device 15003 and wafer 15010 is changed by motor 15006 aschuck 15014 rotating during cleaning process. Control unit 15088 is usedto control the speed of motor 15006 based on speed of motor 15016. Foreach rotation of wafer 15010 or chuck 15014, control unit 15088instructs motor 15006 to turn mega sonic device 15003 clockwise and/orcount clockwise around axis 15011. The increment of rotation angle ofmotor 15006 for each rotation of wafer 15010 or chuck 15014 is,

Δγ=0.5λ/(MN)   (6)

Where, M is distance between axis 15011 and middle position of megasonic device 15003, λ is wavelength of ultra/mega sonic wave, and N isan integer number between 2 to 1000.

After chuck 15014 rotating N rotations, mega sonic device 15003 turns upto total angle of 0.5n/M, where n is an integer number starting from 1.

FIG. 16A to 16D show top view of mega sonic devices according to thepresent invention. Mega sonic device shown in FIG. 4 can be replaced bydifferent shape of mega sonic devices 16003, i.e. triangle or pie shapeas shown in FIG. 16A, rectangle as shown in FIG. 16B, octagon as shownin FIG. 16C, elliptical as shown in FIG. 16D, half cycle to cover halfof wafer as shown in FIG. 16E, and full cycle to cover entire wafer asshown in FIG. 16G. For the embodiment as shown in FIG. 16G, since themega sonic device is covering entire wafer, the wafer or chuck do notneed to retate during the cleaning process. In other words, the gapbetween wafer and mega sonic device is varied as described inembodiments before, and wafer and chuck is kept no rotation.

According to an embodiment, a vertical distance between the ultra/megasonic device and the semiconductor substrate or the wafer may be changedduring the turning of the ultra/mega sonic device or the turning of thesurface of the semiconductor substrate. The change of the verticaldistance may be realized by moving the ultra/mega sonic device itself ormoving the chuck. According to an embodiment, the semiconductorsubstrate rotates, for example, a chuck of the semiconductor substraterotates together with the semiconductor substrate. And within eachrotation of the chuck, the ultra/mega sonic device or the semiconductorsubstrate turns, and the vertical distance between the ultra/mega sonicdevice and the semiconductor substrate changes. Therefore, a betteruniformity of mega sonic power density distribution is implemented.

Although the present invention has been described with respect tocertain embodiments, examples, and applications, it will be apparent tothose skilled in the art that various modifications and changes may bemade without departing from the invention.

1. A method for cleaning semiconductor substrate using ultra/mega sonicdevice, comprising: holding a semiconductor substrate by using a chuck;positioning a ultra/mega sonic device adjacent to the semiconductorsubstrate; injecting a chemical liquid on the semiconductor substrateand into a gap between the semiconductor substrate and the ultra/megasonic device by using at least one nozzle; changing the gap between thesemiconductor substrate and the ultra/mega sonic device by changingangle between the semiconductor substrate and the ultra/mega sonicdevice.
 2. The method of claim 1, wherein the ultra/mega sonic device ispositioned adjacent to a front side of the semiconductor substrate; andthe gap is changed by turning mega sonic device clockwise and/or countclockwise around an axis parallel to the front side of the semiconductorsubstrate.
 3. The method of claim 2, wherein further comprises: rotatingthe chuck around an axis vertical to surface of the semiconductor wafer,and changing the gap between the semiconductor substrate and theultra/mega sonic device for each rotation of the chuck.
 4. The method ofclaim 2, wherein further comprises: moving the ultra/mega sonic devicein a direction vertical to the surface of semiconductor substrate, ormoving the chuck in a direction vertical to the surface of ultra/megasonic device.
 5. The method of claim 1, wherein the ultra/mega sonicdevice is positioned adjacent to a back side of the semiconductorsubstrate; and the gap is changed by turning mega sonic device clockwiseand/or count clockwise around an axis parallel to the back side of thesemiconductor substrate.
 6. The method of claim 5, wherein furthercomprises: rotating the chuck around an axis vertical to surface of thesemiconductor wafer, and changing the gap between the semiconductorsubstrate and the ultra/mega sonic device for each rotation of thechuck.
 7. The method of claim 5, wherein further comprises: moving theultra/mega sonic device in a direction vertical to the surface of thesemiconductor substrate, or moving the chuck in a direction vertical tothe surface of the ultra/mega sonic device.
 8. The method of claim 1,wherein the ultra/mega sonic device is positioned adjacent to a frontside of the semiconductor substrate; and the gap is changed by turningthe front side of the semiconductor substrate clockwise and/or countclockwise around an axis parallel to the surface of the mega sonicdevice.
 9. The method of claim 8, wherein further comprises: rotatingthe chuck around an axis vertical to surface of the semiconductor wafer,and changing the gap between the semiconductor substrate and theultra/mega sonic device for each rotation of the chuck.
 10. The methodof claim 8, wherein further comprises: moving the ultra/mega sonicdevice in a direction vertical to the surface of the semiconductorsubstrate, or moving the chuck in a direction vertical to the surface ofthe ultra/mega sonic device.
 11. The method of claim 1, wherein theultra/mega sonic device is positioned adjacent to a back side of thesemiconductor substrate; and the gap is changed by turning thesemiconductor substrate clockwise and/or count clockwise around an axisparallel to the surface of the mega sonic device.
 12. The method ofclaim 11, wherein further comprises: rotating the chuck around an axisvertical to surface of the semiconductor wafer, and changing the gapbetween the semiconductor substrate and the ultra/mega sonic device foreach rotation of the chuck.
 13. The method of claim 11, wherein furthercomprises: moving the ultra/mega sonic device in a direction vertical tothe surface of the semiconductor substrate, or moving the chuck in adirection vertical to the surface of the ultra/mega sonic device. 14.The method of claim 1, wherein the chuck is kept no rotation duringcleaning process.
 15. An apparatus for cleaning semiconductor substrateusing ultra/mega sonic device, comprising: a chuck holding asemiconductor substrate; a ultra/mega sonic device being positionedadjacent to the semiconductor substrate; at least one nozzle injectingchemical liquid on the semiconductor substrate and into a gap betweenthe semiconductor substrate and the ultra/mega sonic device; a controlunit and a driving mechanism changing the gap between the semiconductorsubstrate and the ultra/mega sonic device by changing the angle betweenthe semiconductor substrate and the ultra/mega sonic device.
 16. Theapparatus of claim 15, wherein the ultra/mega sonic device is positionedadjacent to a front side of the semiconductor substrate; and the controlunit and the driving mechanism changes the gap by turning mega sonicdevice clockwise and/or count clockwise around an axis parallel to thefront side of the semiconductor substrate.
 17. The apparatus of claim16, wherein apparatus further comprising an motor to rotate the chuckaround an axis vertical to the surface of the semiconductor wafer, andthe control unit and the driving mechanism changes the gap between thesemiconductor substrate and the ultra/mega sonic device for eachrotation of the chuck.
 18. The apparatus of claim 16, wherein theapparatus further comprises a second driving moving mechanism beingcontrolled by the control unit, the second driving mechanism drives theultra/mega sonic device to move in a direction vertical to the surfaceof the semiconductor substrate, or to drive the chuck moves in adirection vertical to the surface of the ultra/mega sonic device. 19.The apparatus of claim 15, wherein the ultra/mega sonic device ispositioned adjacent to a back side of the semiconductor substrate; andthe control unit and the driving mechanism changes the gap by turningmega sonic device clockwise and/or count clockwise around an axisparallel to the back side of the semiconductor substrate.
 20. Theapparatus of claim 19, wherein the apparatus further comprises an motorto rotate the chuck around an axis vertical to the surface of thesemiconductor wafer, and the control unit and the driving mechanismchanges the gap between the semiconductor substrate and the ultra/megasonic device for each rotation of the chuck.
 21. The apparatus of claim19, wherein the apparatus further comprises a moving mechanism to drivethe ultra/mega sonic device to move in a direction vertical to thesurface of the semiconductor substrate, or to drive the chuck to move ina direction vertical to the surface of the ultra/mega sonic device. 22.The apparatus of claim 15, wherein the ultra/mega sonic device ispositioned adjacent to a front side of the semiconductor substrate; andthe control unit and the driving mechanism change the gap by turning thesemiconductor substrate clockwise and/or count clockwise around an axisparallel to the surface of the mega sonic device.
 23. The apparatus ofclaim 22, wherein the apparatus further comprises a motor to drive thechuck to rotate around an axis vertical to the surface of thesemiconductor wafer, and the control unit and the driving mechanismchanges the gap between the semiconductor substrate and the ultra/megasonic device changes for each rotation of the chuck.
 24. The apparatusof claim 22, wherein apparatus further comprises a second drivingmechanism being controlled by the control unit, the second drivingmechanism drives the ultra/mega sonic device to move in a directionvertical to the surface of the semiconductor substrate, or to drive thechuck to move in a direction vertical to the surface of the ultra/megasonic device.
 25. The apparatus of claim 15, wherein the ultra/megasonic device is positioned adjacent to a back side of the semiconductorsubstrate; and the control unit and the driving mechanism changes thegap by turning the semiconductor substrate clockwise and/or countclockwise around an axis parallel to the surface of the mega sonicdevice.
 26. The apparatus of claim 25, wherein the apparatus furthercomprises an motor to rotate the chuck around an axis vertical to thesurface of the semiconductor wafer, and the control unit and drivingmechanism changes the gap between the semiconductor substrate and theultra/mega sonic device for each rotation of the chuck.
 27. Theapparatus of claim 25, wherein the apparatus further comprises a seconddriving mechanism being controlled by the control unit, the seconddriving mechanism drives the ultra/mega sonic device to move in adirection vertical to the surface of the semiconductor substrate, or todrive the chuck to move in a direction vertical to the surface of theultra/mega sonic device.